The most surprising Impressionist seen-in-person for me is actually Monet. His large paintings are all about light, of course, and on the reproduced page they're pretty collections of patterned color. In person, howsomeever, they're depthy windows of light and you can practically fall into them.

Particular favorites: the Seine at dawn, all misty and indistinct, and I got an actual chill because I felt I could =really see= what it had looked like, to him through his eyes on the exact morning he had painted it so long ago.

The Seine paintings hardly ever get reproduced in art books. At 4" by 4" they're just pretty squares of colors.

(I was posting to my friend Ineke who is going to an Impressionist exhibit.)